Mailgun is a developer friendly email provider and if you use Mailster you can use them to send your campaigns.
Extensions
Send your Newsletters via SparkPost
With SparkPost you get a solid delivery provider and 100.000 15.000 * mails per month for free. There’s some setup required before you can use this service though.
Mailster and WooCommerce
If you are running your own shop with WooCommerce and would like to get your customers as subscribers to your newsletter campaigns check out the WooCommerce add-on available for free on the WordPress repo.
Reduce false signups with email verification
People signup to your newsletter – great. Not so great if they use none existing email addresses. While there’s no way to be 100% sure if a certain email address exists there’s a way to reduce false signups tremendously.
Send your Newsletters via Amazon’s SES
It’s really recommended to send your newsletters via a dedicate email service provider. One of the big players in this field is Amazon’s Simple Email Service (SES).
Track your clicks with Google Analytics
With Mailster you get many details from your subscribers: clicks, opens, unsubscriptions and bounces. If you watch your websites visitors via an analytics system like Google Analytics or Piwik you can now track you newsletter campaigns with them too.
How can I add a captcha to the sign up form?
Currently are two free plugins available: Mailster Cool Captcha for Forms Mailster reCaptcha™ for Forms You can find the on them WordPress Plugin repo.